JPH09152196A - Refrigeration cycle device and operating method thereof - Google Patents

Abstract

(57) Abstract: To control the amount of refrigerant liquid sucked into a compressor, to prevent damage to the compressor by gradually sucking it into the compressor without returning to the compressor at once. An electric two-way valve 15a is provided between a four-way valve 5 and a suction side of the compressor 1, and the electric two-way valve 15a is opened little by little at the same time when the compressor 1 is started or after a lapse of a predetermined time. A large amount of refrigerant liquid is sucked into the compressor 1 little by little without returning to the compressor 1 all at once, and damage to the compressor 1 is prevented.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to refrigerant control in a refrigeration cycle.

[0002]

2. Description of the Related Art FIG. 8 is a refrigerant circuit diagram of a remote heat pump chiller equipped with a conventional refrigerant liquid injection type compressor disclosed in Japanese Patent Laid-Open No. 4-340064. In the figure, 1
Is a refrigerant liquid injection type compressor, 2 is a utilization side heat exchanger that can take out cold water or cold air during cooling operation, and hot water or warm air during heating operation, 3 is a heat source side heat exchanger, and 4 is a heat exchanger Blower, 5 is a four-way valve that switches this heating and cooling circuit, 6
Is an expansion mechanism, 7 is a liquid receiver, 8a to 8d are cooling / heating switching check valves, 9 is a solenoid valve of a refrigerant liquid injection pipe, 10a, 10b
Is a refrigerant liquid injection pipe, 11a is a refrigerant pipe in the indoor unit 12, 11b is a refrigerant pipe in the outdoor unit 13, 11c is a gas side refrigerant pipe connecting the indoor unit 12 and the outdoor unit 13, and 11d is an indoor unit 12. Liquid-side refrigerant pipe for connecting the outdoor unit 13, 14
Is a mist separator.

Next, the operation will be described. During the cooling operation, the high-pressure refrigerant gas compressed by the compressor 1 passes from the mist separator 14 through the four-way valve 5 and the gas-side refrigerant pipe 11c, exchanges heat with air in the heat-source-side heat exchanger 3, and is condensed to form a high-pressure refrigerant. Become a liquid. The condensed high-pressure refrigerant liquid passes from the liquid-side refrigerant pipe 11d through the cooling / heating switching check valve 8a and the liquid receiver 7 to the expansion mechanism 6
Is decompressed, passes through the cooling / heating switching check valve 8d, exchanges heat with water in the use-side heat exchanger 2 and evaporates to become a low-pressure refrigerant gas. The low-pressure refrigerant gas that has evaporated is the four-way valve 5 and the refrigerant pipe 1.
It is sucked into the compressor 1 through 1a.

During heating operation, high-pressure refrigerant gas compressed by the compressor 1 passes from the mist separator 14 through the four-way valve 5,
Heat is exchanged with water in the use side heat exchanger 2 and condensed to become a high-pressure refrigerant liquid. The condensed high-pressure refrigerant liquid is used for the check valve 8 for switching between cooling and heating.
b, the pressure is reduced by the expansion mechanism 6 through the liquid receiver 7, passes through the cooling / heating switching check valve 8c, and the liquid-side refrigerant pipe 11d to evaporate by exchanging heat with air in the heat source-side heat exchanger 3 to form a low-pressure refrigerant gas. become. The evaporated low-pressure refrigerant gas is used as the gas-side refrigerant pipe 11
It is taken into the compressor 1 through the four-way valve c, the four-way valve 5 and the refrigerant pipe 11a.

[0005]

Since the conventional refrigeration cycle is configured as described above, the outdoor unit 13 serves as a condenser during the cooling operation, and the condensed refrigerant liquid is supplied to the outdoor unit 13 and the liquid side refrigerant pipe 11d. It has accumulated. Gas-side refrigerant pipe 11 that connects the indoor unit 12 and the outdoor unit 13 like a remote type
When c and the liquid-side refrigerant pipe 11d are long and the pipe diameter is large, the amount of refrigerant liquid accumulated inside the pipe increases. When the cooling operation is switched to the heating operation in this state, a large amount of the refrigerant liquid accumulated in the outdoor unit 13 and the liquid-side refrigerant pipe 11d is immediately compressed.
There is a problem that the compressor is damaged by returning to (liquid back) and compressing the refrigerant liquid. In order to solve this, it was necessary to provide a large gas-liquid separator (accumulator) upstream of the compressor suction section to prevent a large amount of refrigerant liquid returning from the outdoor unit 13 and the liquid side refrigerant pipe 11d. Since a gas-liquid separator having a large capacity is required, there is a problem that the cost becomes high.

The present invention has been made in order to solve the above problems, and an object thereof is to prevent damage to the compressor due to liquid back by adjusting the amount of refrigerant liquid sucked into the compressor.

[0007]

A refrigeration cycle apparatus according to claim 1 of the present invention is provided with an electric two-way valve between a suction side of a compressor and a four-way valve.

The operation method of the refrigeration cycle apparatus according to the second and third aspects of the present invention is a two-way electric two-way operation at the same time when the compressor is started or after a certain time (25 seconds to 35 seconds) has elapsed. The valve was opened.

In the refrigerating cycle apparatus operating method according to the fourth and fifth aspects of the present invention, the compressor capacity control is minimized (2) at the same time as the start of the compressor or after a fixed time (25 seconds to 35 seconds) has elapsed.
Hold at 0% position and slightly (2 °
The electric two-way valve is opened by 5 ° each.

In the refrigeration cycle apparatus operating method according to the sixth and seventh aspects of the present invention, the compressor capacity control is minimized (2) at the same time as the start of the compressor or after a lapse of a fixed time (25 seconds to 35 seconds).
Hold at 0% position and slightly (2 °
Open the motorized two-way valve by ~ 5 °). Meanwhile, when the decrease rate of the low pressure is small, the compressor capacity control is 5% to 15%.
It is to increase by%.

In the refrigeration cycle apparatus according to claim 8 of the present invention, one indoor unit is provided with a plurality of outdoor units, and electric power is provided between the four-way valve and the compressor suction side and in each outdoor unit gas side refrigerant pipe. It has a two-way valve.

According to the ninth and tenth aspects of the present invention, the operation method of the refrigeration cycle apparatus is such that the electric two-way valve on the compressor side is slightly moved (10 seconds) at the same time as the compressor is started or after a fixed time (25 seconds to 35 seconds) has elapsed. (° to 15 °) open, the electric two-way valve of each outdoor unit is opened one by low pressure drop and all the electric two-way valves of all outdoor units are fully opened, then the electric two-way valve on the compressor side. Is opened little by little (2 ° to 5 °).

In the refrigeration cycle apparatus operating method according to the eleventh and twelfth aspects of the present invention, the electric two-way valve on the compressor side is slightly moved (10 seconds) at the same time as the start of the compressor or after a predetermined time (25 seconds to 35 seconds) has elapsed. ° -15 °) open, the electric two-way valves of each outdoor unit are opened one by one due to the low pressure drop, and the electric two-way valves of all the outdoor units are fully opened. Open the one-way valve little by little (2 ° to 5 °). Meanwhile, when the decrease rate of the low pressure is small, the compressor capacity control is 5% to 1%.
Increase by 5%.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a refrigerant circuit diagram thereof. In the figure, 1 is a refrigerant liquid injection type compressor, 2 is a utilization side heat exchanger capable of taking out cold water or cold air during cooling operation, and hot water or warm air during heating operation. 3 is a heat source side heat exchanger, 4 is a blower for the heat exchanger, 5 is a four-way valve that switches the heating and cooling circuit, 6 is an expansion mechanism, 7 is a liquid receiver, and 8a to 8d are check valves for switching heating and cooling, Reference numeral 9 denotes a solenoid valve for a refrigerant liquid injection pipe, 10a,
Reference numeral 10b is a refrigerant liquid injection pipe, 11a is a refrigerant pipe inside the indoor unit 12, 11b is a refrigerant pipe inside the outdoor unit 13, 11c is a gas side refrigerant pipe connecting the indoor unit 12 and the outdoor unit 13, 11
d is a liquid-side refrigerant pipe connecting the indoor unit 12 and the outdoor unit 13,
Reference numeral 14 is a mist separator, and 15a is an electric two-way valve.
The compressor 1 has a continuous capacity control mechanism of 20 to 100%.

Next, the operation will be described. During the cooling operation, the high-pressure refrigerant gas compressed by the compressor 1 passes from the mist separator 14 through the four-way valve 5 and the gas-side refrigerant pipe 11c, exchanges heat with air in the heat-source-side heat exchanger 3, and is condensed to form a high-pressure refrigerant. Become a liquid. The condensed high-pressure refrigerant liquid passes from the liquid-side refrigerant pipe 11d through the cooling / heating switching check valve 8a and the liquid receiver 7 to the expansion mechanism 6
Is decompressed, passes through the cooling / heating switching check valve 8d, exchanges heat with water in the use-side heat exchanger 2 and evaporates to become a low-pressure refrigerant gas. The low-pressure refrigerant gas that has evaporated is the four-way valve 5 and the refrigerant pipe 1.
It is sucked into the compressor 1 through 1a.

During heating operation, high-pressure refrigerant gas compressed by the compressor 1 passes from the mist separator 14 through the four-way valve 5,
Heat is exchanged with water in the use side heat exchanger 2 and condensed to become a high-pressure refrigerant liquid. The condensed high-pressure refrigerant liquid is used for the check valve 8 for switching between cooling and heating.
b, the pressure is reduced by the expansion mechanism 6 through the liquid receiver 7, passes through the cooling / heating switching check valve 8c, and the liquid-side refrigerant pipe 11d to evaporate by exchanging heat with air in the heat source-side heat exchanger 3 to form a low-pressure refrigerant gas. become. The evaporated low-pressure refrigerant gas is used as the gas-side refrigerant pipe 11
It is taken into the compressor 1 through the four-way valve c, the four-way valve 5 and the refrigerant pipe 11a.

Here, since the heat source side heat exchanger 3 is used as a condenser during the cooling operation, the refrigerant liquid is accumulated in the heat source side heat exchanger 3, the liquid side refrigerant pipe 11b, and the gas side refrigerant pipe 11c. At the time of switching from the cooling operation to the heating operation, the heat source side heat exchanger 3 functions as an evaporator, and the evaporated refrigerant gas and the refrigerant liquid that cannot be partially evaporated are gas side refrigerant pipes that connect the indoor unit 12 and the outdoor unit 13. The refrigerant liquid accumulated in 11c flows to the electric two-way valve 15a on the compressor 1 side. Compressor 1
A large amount of refrigerant liquid flowing to the electric two-way valve 15a is opened by opening the electric two-way valve 15a little by little (2 ° to 5 °) at the same time as the start or after a certain time (25 seconds to 35 seconds) has elapsed. It is sucked into the compressor 1 little by little without returning to the compressor 1 at a stroke, and damage to the compressor 1 is prevented. FIG. 2 shows a flowchart.

Embodiment 2. The structure itself is similar to that shown in FIG. Similar to the first embodiment, when switching from the cooling operation to the heating operation, the heat source side heat exchanger 3 becomes an evaporator,
Evaporated refrigerant gas and refrigerant liquid that could not be partially evaporated,
Gas-side refrigerant pipe 11 that connects the indoor unit 12 and the outdoor unit 13
It flows to the electric two-way valve 15a on the compressor 1 side together with the refrigerant liquid accumulated in c. Simultaneously with the start of the compressor 1 or after a certain time (25 seconds to 35 seconds) has passed, the capacity control of the compressor 1 is kept at a minimum (20% position), and the pressure of the low pressure gradually decreases (2 ° to 5 °) little by little. The electric two-way valve 15a is opened. It is determined that a large amount of the refrigerant liquid that has flown up to the electric two-way valve 15a and has accumulated due to the decrease in the low pressure has decreased.
This prevents damage to the compressor 1 by sucking a large amount of the refrigerant liquid flowing up to the electric two-way valve 15a into the compressor 1 little by little without returning to the compressor 1 at once. FIG. 3 shows a flowchart.

Embodiment 3 The structure itself is similar to that shown in FIG. Similar to the first embodiment, when switching from the cooling operation to the heating operation, the heat source side heat exchanger 3 becomes an evaporator,
Evaporated refrigerant gas and refrigerant liquid that could not be partially evaporated,
Gas-side refrigerant pipe 11 that connects the indoor unit 12 and the outdoor unit 13
It flows to the electric two-way valve 15a on the compressor 1 side together with the refrigerant liquid accumulated in c. Simultaneously with the start of the compressor 1 or after a certain time (25 seconds to 35 seconds) has passed, the capacity control of the compressor 1 is kept at a minimum (20% position), and the pressure of the low pressure gradually decreases (2 ° to 5 °) little by little. Open the electric two-way valve 15a,
When the decrease rate of the low pressure is small, the compressor 1 capacity control is increased by 5% to 15%. It is judged that the large amount of the refrigerant liquid that has flowed up to the electric two-way valve 15a and accumulated is reduced due to the decrease in the low pressure, and the reduction ratio of the low pressure is decreased, so that the gas is sucked into the compressor 1 a little more. It is determined that you can let it. As a result, a large amount of the refrigerant liquid that has flowed to the electric two-way valve 15a is sucked into the compressor 1 little by little without returning to the compressor 1 all at once, so that damage to the compressor 1 can be prevented, and the refrigerant in a short time. The liquid can be collected. FIG. 4 shows a flowchart.

Embodiment 4 FIG. 5 shows a refrigerant circuit diagram according to the fourth embodiment. FIG. 5 shows the case where one indoor unit has a plurality of outdoor units, and 15b is an electric two-way valve attached to each outdoor unit 13. Even when one indoor unit 12 has a plurality of outdoor units 13, the heat source side heat exchanger 3 becomes an evaporator when switching from the cooling operation to the heating operation as in the first embodiment. However, since there are multiple outdoor units 13,
The amount of refrigerant liquid accumulated in the outdoor unit 13 also increases, and the electric two-way valve 15b is attached to each outdoor unit 13 and the outdoor units 13 are separated one by one after starting.
The amount of the refrigerant liquid returned to the compressor 1 is adjusted by collecting the refrigerant liquid from the. As an operation, the electric two-way valve 15a on the compressor 1 side is slightly opened (10 ° to 15 °) at the same time when the compressor 1 is started or after a certain time (25 seconds to 35 seconds) elapses, and the electric two valves of each outdoor unit 13 are electrically operated. The one-way valves 15b are fully opened one by one due to the reduction of the low pressure, and the electric two-way valves 15b of all the outdoor units 13 are fully opened. ) Open each. It is determined that a large amount of the refrigerant liquid accumulated in each outdoor unit 13 and the refrigerant pipe has decreased due to the decrease in the low pressure. As a result, a large amount of the refrigerant liquid is sucked into the compressor 1 little by little without returning to the compressor 1 all at once, thereby preventing damage to the compressor 1. FIG. 6 shows a flowchart.

Embodiment 5 The structure itself is similar to that shown in FIG. Similar to the fourth embodiment, each outdoor unit 13
The motor-operated two-way valve 15b is attached to and the amount of the refrigerant liquid returned to the compressor 1 is adjusted by collecting the refrigerant liquid from the outdoor unit 13 one by one after the start. As the operation, the electric two-way valve 15a on the side of the compressor 1 is slightly opened (10 ° to 15 °) at the same time as the start of the compressor 1 or after a certain time (25 seconds to 35 seconds) has passed,
The electric two-way valves 15b of each of the outdoor units 13 are fully opened one by one due to a decrease in low-pressure pressure, and the electric two-way valves 1 of all the outdoor units 13 are opened.
After fully opening 5b, the electric two-way valve 15a on the compressor 1 side
Are opened little by little (2 ° to 5 °). When the decrease rate of the low pressure is small, the compressor 1 capacity control is increased by 5% to 15%. It was judged that a large amount of the refrigerant liquid accumulated in each outdoor unit 13 and the refrigerant pipe decreased due to the decrease in the low pressure, and the decrease rate of the low pressure decreased, so that the gas was sucked into the compressor 1 a little more. It is determined that you can let it.
As a result, a large amount of the refrigerant liquid is sucked into the compressor 1 little by little without returning to the compressor 1 all at once, thereby preventing damage to the compressor 1. FIG. 7 shows a flowchart.

[0022]

As described above, according to the first aspect of the present invention, since the electric two-way valve is provided between the compressor suction side and the four-way valve, the suction pipe flow passage area is gradually increased, The refrigerant liquid accumulated inside the pipe can be sucked into the compressor little by little.

According to the second and third aspects of the present invention, the electric two-way valve is opened little by little (2 ° to 5 °) at the same time as the start of the compressor or after the elapse of a certain time (25 to 35 seconds). With this, a large amount of the refrigerant liquid is sucked into the compressor little by little without returning to the compressor 1 at a stroke, and the damage of the compressor can be prevented.

According to the fourth and fifth aspects of the present invention, the compressor capacity control is kept at the minimum (20% position) at the same time as the start of the compressor or after the elapse of a certain time (25 seconds to 35 seconds), and the low pressure By opening the electric two-way valve little by little (2 ° to 5 °) due to the decrease, the suction pipe flow passage area is adjusted by the decrease in the low pressure, and a large amount of the refrigerant liquid is not returned to the compressor all at once. Even compared with the items 2 and 3, the damage to the compressor can be prevented more reliably.

According to the sixth and seventh aspects of the present invention, the compressor capacity control is kept at the minimum (20% position) at the same time as the start of the compressor or after a fixed time (25 seconds to 35 seconds) elapses. By opening the electric two-way valve little by little (2 ° to 5 °) due to the decrease, and increasing the compressor capacity control when the low pressure decrease rate is small, a large amount of refrigerant liquid is not returned to the compressor all at once. Compared with the items 4 and 5, the damage to the compressor can be prevented more reliably.

According to claim 8 of the present invention, one indoor unit is provided with a plurality of outdoor units, and an electric two-way valve is provided between the four-way valve and the compressor suction side and in each outdoor unit gas side refrigerant pipe. Since it is provided, the suction pipe flow passage area can be gradually increased, and the refrigerant liquid accumulated inside the pipe can be sucked into the compressor little by little.

According to the ninth and tenth aspects of the present invention, the electric two-way valve on the compressor side is slightly opened (10 ° to 15 °) at the same time as the start of the compressor or after a lapse of a fixed time (25 seconds to 35 seconds). After the electric two-way valves of each outdoor unit are opened one by one due to the low pressure drop, the electric two-way valves of all the outdoor units are fully opened. The flow path area is gradually increased by the electric two-way valve on the compressor side and each outdoor unit, and the refrigerant liquid accumulated inside the pipe is sucked into the compressor little by little. Therefore, damage to the compressor can be prevented more reliably without returning a large amount of refrigerant liquid to the compressor at once.

According to the eleventh and twelfth aspects of the present invention, the electric two-way valve on the compressor side is slightly opened (10 ° to 15 °) at the same time as the start of the compressor or after a fixed time (25 seconds to 35 seconds) has elapsed. After the electric two-way valves of each outdoor unit are opened one by one due to the low pressure drop, the electric two-way valves of all the outdoor units are fully opened. ~ 5 °) each. In the meantime, when the reduction rate of the low pressure is small, the compressor capacity control is increased by 5% to 15%, so that a large amount of the refrigerant liquid is not returned to the compressor all at once.
Even compared with 10, it is possible to more reliably prevent damage to the compressor.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram according to Embodiment 1 of the present invention.

FIG. 2 is a flow chart diagram of the refrigeration cycle according to the first embodiment of the present invention.

FIG. 3 is a flow chart diagram of a refrigeration cycle according to Embodiment 2 of the present invention.

FIG. 4 is a flow chart diagram of a refrigeration cycle according to a third embodiment of the present invention.

FIG. 5 is a refrigerant circuit diagram according to a fourth embodiment of the present invention.

FIG. 6 is a flow chart diagram of a refrigeration cycle according to Embodiment 4 of the present invention.

FIG. 7 is a flow chart diagram of a refrigeration cycle according to a fifth embodiment of the present invention.

FIG. 8 is a refrigerant circuit diagram of a conventional remote heat pump chiller.

[Explanation of symbols]

1 compressor, 2 utilization side heat exchanger, 3 heat source side heat exchanger, 5 four-way valve, 11a-11d refrigerant piping, 15a,
15b Electric two-way valve.

Claims (12)

[Claims] 1. A compressor for injecting a refrigerant liquid, a utilization side heat exchanger capable of taking out cold water or cold air during cooling operation, and hot water or hot air during heating operation, and a four-way valve for switching between heating and cooling circuits. In a refrigeration cycle apparatus including a heat source side heat exchanger installed at a distance, the compressor, the utilization side heat exchanger, the four-way valve, and a refrigerant pipe connecting the heat source side heat exchanger, the compression An electric two-way valve is provided between the suction side of the machine and the four-way valve. 2. The method for operating a refrigeration cycle apparatus according to claim 1, wherein the electric two-way valve is opened by 2 ° to 5 ° at the same time when the compressor is started. 3. The method for operating a refrigeration cycle apparatus according to claim 1, wherein the electric two-way valve is opened by 2 ° to 5 ° after 25 seconds to 35 seconds have elapsed since the compressor was started. 4. The electric two-way valve is set to 2 ° to 20 ° while the compressor capacity control is kept at the minimum 20% position at the same time when the compressor is started.
The method for operating a refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is opened at 5 ° intervals. 5. The electric two-way valve is opened by 2 ° to 5 ° in a state where the compressor capacity control is kept at the minimum 20% position after 25 seconds to 35 seconds have elapsed since the compressor was started. The method for operating the refrigeration cycle apparatus according to claim 1. 6. When the compressor capacity control is maintained at the minimum 20% position, the compressor capacity control is increased by 5% to 15% at the same time when the low pressure is decreased at the same time when the compressor is started. The method for operating a refrigeration cycle apparatus according to claim 1, wherein the two-way valve is opened by 2 ° to 5 °. 7. The compressor capacity control is kept at 5% when the low pressure drop rate is small after 25 seconds to 35 seconds have elapsed since the compressor was started with the compressor capacity control kept at the minimum 20% position. The operating method of the refrigeration cycle apparatus according to claim 1, wherein the electric two-way valve is opened by 2 ° to 5 ° each by -15%. 8. The refrigeration cycle apparatus according to claim 1, wherein a plurality of heat source side heat exchangers are provided, and an electric two-way valve is provided between each heat source side heat exchanger and the four-way valve. 9. Simultaneously with starting of the compressor, the electric two-way valve on the compressor side is opened at 10 ° to 15 °, and thereafter, the electric two-way valve on each heat source side heat exchanger side is fully opened one by one to fully open each of the above. 9. The refrigeration cycle apparatus according to claim 8, wherein the electric two-way valve on the compressor side is opened by 2 ° to 5 ° after the electric two-way valve on the heat source side heat exchanger side is fully opened. How to operate. 10. The electric two-way valve on the compressor side is opened 10 ° to 15 ° after 25 seconds to 35 seconds have elapsed since the compressor was started,
After that, the electric two-way valves on each heat source side heat exchanger side are fully opened one by one to fully open all the electric two-way valves on each heat source side heat exchanger side, and then the electric two-way valve on the compressor side. 2 ° to 5 °
9. The method for operating a refrigeration cycle apparatus according to claim 8, wherein the refrigeration cycle apparatus is opened one by one. 11. The electric two-way valve on the compressor side is opened at 10 ° to 15 ° at the same time when the compressor is started, and when the reduction rate of the low pressure is small, the compressor capacity control is increased by 5% to 15%. After the electric two-way valves on the heat source side heat exchanger side are fully opened one by one, all the electric two-way valves on each heat source side heat exchanger side are fully opened.
9. The method for operating a refrigeration cycle apparatus according to claim 8, wherein the electric two-way valve on the compressor side is opened by 2 ° to 5 °. 12. The electric two-way valve on the compressor side is opened at 10 ° to 15 ° after 25 seconds to 35 seconds have elapsed after starting the compressor,
Compressor capacity control is 5% when low pressure drop rate is small
-15% each, the electric two-way valves on each heat source side heat exchanger side are fully opened one by one, and all the electric two-way valves on each heat source side heat exchanger side are fully opened. 2 electric two-way valve
9. The method for operating a refrigerating cycle device according to claim 8, wherein the refrigerating cycle device is opened every 5 °.